The Old Shale Stitch is a version of the famous Shetland Lace Knitting Stitch which produces an attractive wave like effect.
It is simple and rather rhythmic to work.
Cast on a multiple of 18 stitches +1.
Row 1 : Knit to end
Row 2: Purl to end
Row 3: *K1, [K2tog] 3 times, [YO,K1] 5 times, YO,[K2tog] 3 times, repeat from * to last stitch, K1
Row 4: Knit to end
These 4 rows complete the pattern.